This invention relates to a cage made of synthetic resin for a self-aligning roller bearing.
FIGS. 9 and 10 show a prior art cage of this type. It comprises a pair of annular bodies 30 integrally coupled together by means of a plurality of columns 31 arranged at equal circumferential intervals to define pockets 33 for retaining spherical rollers 32 between the adjacent columns 31.
The columns 31 have their side face 34 arcuately curved in such a shape as to conform to the outer periphery of the spherical rollers 32 so that the side faces 34 and the spherical rollers will make a surface-to-surface contact with each other when the bearing is in operation.
With such a prior art cage, since clearances 35 are formed between the side faces 34 of the columns 31 and the outer periphery of the spherical rollers 32 to allow the spherical rollers to move in the clearances 34, they tend to skew. Also, since the size of the clearances 35 is uniform in the axial direction of the spherical rollers 32, the flowability of lubricating oil is poor.